MD Dept. of Natural Resources, Chesapeake Bay Mainstem Water Quality Monitoring 2022

QUALITY ASSURANCE/QUALITY CONTROL. Maryland Department of Natural Resources followed specific procedures to ensure that the mainstem component of the Chesapeake Bay Water Quality Monitoring Program design was properly implemented and managed with sufficient accuracy, precision, and detection limits. Accuracy (closeness to the true value) of collected data was controlled and assured by proper use, calibration, and maintenance of both field and laboratory equipment for the measurement of physical and chemical parameters. The procedures to control and assure the accuracy of field measurements involved the calibration of field instruments, the verification of calibrations, and equipment maintenance. Most of the details of how data acquired with YSI sondes were quality assured and quality controlled are described in the process description elements in the Lineage portion of this metadata record. Daily quality control checks, which included the running of blanks and standards, were used to control and assure laboratory accuracy. Accuracy of Chesapeake Biological Laboratory, Nutrient Analytical Services Laboratory (CBL NASL) results was also assessed through DNR's participation in the Chesapeake Bay Coordinated Split Sample Program (CSSP) a split sampling program in which five laboratories involved in Chesapeake Bay monitoring analyze the coordinated split samples. CSSP was established in June 1989 to establish a measure of comparability between sampling and analytical operations for water quality monitoring throughout the Chesapeake Bay and its tributaries. DNR followed the protocols in the Chesapeake Bay Coordinated Split Sample Program Implementation Guidelines (EPA 1991) and its revisions. Split samples were collected quarterly. Results were analyzed by appropriate statistical methods to determine if results differed significantly among labs. If a difference occurred, discussions began regarding techniques and potential methods changes to resolve discrepancies. ADDITIONAL COMMENTS January 2022: Scoping is a term used to describe situations when strong currents and or winds make it difficult to maintain the water quality data sonde at a depth long enough for readings to stabilize. Meter scoping was noted at stations CB3.3C, CB4.1C, CB4.2C, and CB4.3C. There was no pycnocline at stations CB2.2, CB4.1C, CB4.2C, CB4.3C, CB4.4, CB5.1, and CB5.2, and above pycnocline and below pycnocline water samples were collected at 1/3 and 2/3 of station total water column depth. February 2022: Meter scoping was noted at stations CB4.1C, CB4.2C, and CB4.3C. The surface conductivity changed at station CB5.2, so above pycnocline and below pycnocline water samples were collected at 1/3 and 2/3 of station total water column depth. Afternoon rain showers occurred the day before sampling at stations CB3.3C, CB4.1C, CB4.2C, and CB4.3C. March 2022: A pycnocline was not evident at station CB2.2. Above pycnocline and below pycnocline water samples were collected at 1/3 and 2/3 of total water column depth at this station. April 2022: There was no pycnocline at station CB2.2, and above pycnocline and below pycnocline water samples were collected at 1/3 and 2/3 of station total water column depth. The surface conductivity reading at station CB3.2 would not stabilize. May 2022: Scattered overnight thunderstorms were noted at stations sampled on 16-May. Numerous afternoon thunderstorms, some severe, occurred the day before sampling activities on 17-May. There was no pycnocline at station CB2.2, so above pycnocline and below pycnocline water samples were collected at 1/3 and 2/3 of station total water column depth. Surface conductivity readings changed between the beginning and end of the hydrocast at stations CB3.2, BC3.3C, CB4.1E, and CB5.3. June 2022: The first June mainstem survey was conducted June 6-8. There was no pycnocline at station CB3.1, and above pycnocline and below pycnocline water samples were collected at 1/3 and 2/3 of station total water column depth. The second June mainstem survey was conducted June 28-30. Station CB4.1C bottom and below pycnocline sample waters had hydrogen sulfide odors. Hazy conditions were reported at stations CB3.1 and CB3.2. At station CB3.1, the dissolved oxygen reading at 9m depth was double-checked. A pycnocline was not evident at stations CB2.2 and CB4.1E. Above pycnocline and below pycnocline water samples were collected at 1/3 and 2/3 of total water column depth at these stations. Thin clouds were observed at stations CB5.1 and CB5.2. July 2022: The first July mainstem cruise was conducted July 12-14. There was no pycnocline at stations CB2.2 and CB3.2, and above pycnocline and below pycnocline water samples were collected at 1/3 and 2/3 of the total water column depth at these stations. Hazy conditions were reported at stations CB4.4, CB5.1, CB5.2, and CB5.3. At station CB4.1W, the dissolved oxygen reading at 1m depth was double-checked. An odor of hydrogen sulfide, at times slight, was present in bottom and below pycnocline water samples collected at stations CB4.1C, CB4.1E, and CB4.2C. Water column measurements only (no pigment or nutrient samples) were collected during the second July (26-27) mainstem survey. August 2022: The first August mainstem cruise was conducted August 8-10 and hazy conditions were reported during this cruise. Stations CB4.1C and CB4.2C bottom and below pycnocline sample waters had a hydrogen sulfide odor. A hydrogen sulfide odor was noted in the bottom water sample collected at station CB3.3C. There was no pycnocline at stations CB2.2 and CB3.2, so above pycnocline and below pycnocline water samples were collected at 1/3 and 2/3 of the total water column depth, respectively. Water pump issues occurred while sampling station CB5.3. The second August mainstem survey was conducted August 22-23. A hydrogen sulfide odor was noted in bottom and below pycnocline water samples collected at stations CB3.3C, CB4.1C, CB4.1E and CB4.3E. Station CB4.2C below pycnocline sample waters had a hydrogen sulfide odor. At station CB5.3, the dissolved oxygen readings at 6m and 7.8m depths were double-checked; and the secchi reading was double-checked at station CB4.2C. At station CB5.1, the water pump experienced mechanical issues at 16.0m. September 2022: A hydrogen sulfide odor was noted in bottom water sample collected at station CB4.1C. October 2022: Hurricane Ian passed through the region a few days before the October mainstem cruise. There was no pycnocline at stations CB2.2, CB4.1C, CB4.2C, CB4.3C, CB4.4, and CB5.1, so above pycnocline and below pycnocline water samples were collected at 1/3 and 2/3 of the total water column depth. The water pump hose came off at 11.0m on station CB3.2. A vessel passed during sampling at station CB4.2C. November 2022: Overnight rain was noted at stations sampled on 16-November. There was no pycnocline at stations CB4.4, CB5.1, CB5.2, and CB5.3, so above pycnocline and below pycnocline water samples were collected at 1/3 and 2/3 of the total water column depth. A large cargo ship passed station CB5.2 prior to sampling. December 2022: Very heavy fog was present during sampling on 6-December and 7-December. There was no pycnocline at stations CB4.2C, CB4.3C, CB4.4, CB5.1, CB5.2, and CB5.3, so above pycnocline and below pycnocline water samples were collected at 1/3 and 2/3 of the total water column depth. The sonde/bottle sampling array touched bottom at stations CB3.3C and CB4.1C. It was noted that the Coast Guard changed buoys at or near station CB2.2, the bottom sample at station CB4.2C was very dark, and thin clouds were observed at station CB5.2.